Method and device for striking out the waste or use from punched sheet workpieces



S p 1962 F. SCHROTER 3,055,275

METHOD AND DEVICE FOR STRIKING OUT THE WASTE OR USE FROM PUNCHED SHEET WORKPIECES Filed Feb. 16. 1959 4 Sheets-Sheet 1 JRF p 1962 F. SCHROTER 3,055,275

- METHOD AND DEVICE FOR STRIKING OUT THE WASTE OR USE FROM PUNCHED SHEET WORKPIECES Filed Feb. 16, 1959 4 Sheets-Sheet 2 pt- 25, 1952 F. scHRoTE 3,055,275

METHOD AND DEVICE FOR STRIKING OUT THE WASTE OR USE FROM PUNCHED SHEET WORKPIECES Filed Feb. 16, 1959 4 Sheets-Sheet 3 p 1962 F. SCHROTER 3,055,275

METHOD AND DEVICE FOR STRIKING OUT THE WASTE OR USE FROM PUNCHED SHEET WORKPIECES Filed Feb. 16, 1959 4 Sheets-Sheet 4 l 1 a I 5 I I 4 I I 4 United States Patent METHOD AND DEVECE FUR STRKKIING (BUT THE WASTE OR USE FROM PUNGHED SHEET WORK- PKECES Friedrich Schroter, Hannover, Germany (Am Waidehen 8, lsernhagen NB-Sud, Germany) Filed Feb. 16, W59, Ser. No. 7%,e43 Claims priority, appiication Germany Feb. 22, 1958 8 Qlainrs. (Ct. %36) Methods and apparatus for striking out the waste or use from punched sheet workpieces, particularly of paper, cardboard, or the like, are already known. When parts are punched from these workpieces the fibrous nature of the material causes always a part of the fibers to remain unsevered so that even workpieces surrounded by closed punched lines do not automatically fall away from the workpiece as soon as the support of the punchedout workpiece part is removed; on the contrary, special steps are required to strike out parts of the workpiece which has actually not been punched but only incised. This is eifected by severing the cohesion of such parts to the other workpiece parts to enable a complete separation of these parts.

The striking-out operation has already been performed mechanically or by machines. This has been effected in various ways. In the first striking-out method, cylinders are used, between which the workpiece is passed through. One of the cylinders carries needles, which pierce the parts to be struck out and thus remove them. In the second method the punched workpiece is introduced between two plates, the lower one of Which has apertures the shape of which agrees with that of the workpiece parts to be struck out whereas the upper plate has male pieces of the same shape so that the approach of the two plates causes the male pieces to engage the workpiece parts to be struck out and to force them out through the apertures in the lower plate; then the plates are removed and thereafter the remainder of the workpiece is removed too.

It is possible and usual to leave in certain cases individual workpiece parts unremoved in order to ensure a sufiicient coherence of the workpiece, particularly in machines the workpieces are automatically fed from the feeding station to the punching station or from the punching station to the striking-out and laying-out stations. In some cases it is necessary to leave that edge of the sheet which is engaged by the grippers of the gripper rods used for conveying, the so-called gripper edge, on the sheet; in these cases a special operation was required to remove this gripper edge.

Both striking-out methods have already been incorporated in the automatic sequence of operation of punching machines, so-called automatic punching machines, wherein a printed sheet introduced into the machine is completely punched and layed-out after the waste has been removed unless the parts struck out are not used themselves and the remainder of the sheet workpiece is waste.

Both methods have advantages and disadvantages. Besides, they .are substantially restricted each to a specific type of punching machine. More particularly, the second method has been used in punching machines having flat dies because it can be particularly conveniently incorporated in the sequence of operation of such punching machines whereas the first method has mainly been used in cylinder-type punching machines.

A particularly grave disadvantage of the previously known striking-out methods in machines having fiat dies resides in that narrow waste strips .as often occur in the form of strips only a few millimeters Wide tend to separate from the adjoining workpiece parts only along a part 3,655,275 Patented Sept. 25, 1962 of their boundary lines during the striking-out operation so that they are folded over rather than struck out. This is so because the male pieces which exert the striking-out forces on the workpiece parts to be removed fit the apertures of the template-like plate, through which apertures the parts struck out are to be removed, with a clearance, which for reasons of economical manufacture and setting up exceeds the thickness of the workpiece, e.g., the cardboard so that the strips which are only folded over can be accommodated between the workpieces and are caught when the plates are moved apart and the workpieces are conveyed further. This results in disturbances leading to the standstill of the machine and the disturbance, although small in itself, causes relatively large losses in output owing to the high hourly outputs of present-day automatic punching machines of this type.

it is an object of the present invention to remove these difiiculties and to ensure a trouble-free operation of machines of this type.

The method proposed according to the invention of striking out the waste or the use of punched sheet workpieces, particularly of paper, cardboard or the like, is characterized in that the workpiece parts to be struck out are gripped on both sides, struck out and guided on a predetermined path until they are released.

This positive gripping of the workpiece parts striking out even uses or waste of the most intricate and complex shapes whereas, on the other hand, simple striking-out operations, e.g. on sheets of corrugated cardboard, can be performed with perfect reliability and without any trouble.

When the workpiece parts to be struck out are gripped only On an area which is small compared to their surface area it is no longer necessary to design the pressure pieces, which will hereinafter be referred to as rams, in conformity with the boundary edge of the workpiece parts to be struck out; these rams may be formed with a uniform cross-section, identical among themselves, whereas the same small area of the rams enables them to act even on workpiece parts to be struck out which have a very small area so that even workpiece parts having a very small area can be struck out.

The workpiece is suitably held during the striking-out operation in position against the striking-out direction. Whereas the supporting of the workpiece on the abovementioned template having the passage openings for the workpiece parts struck out would appear sufiicient, it has proved suitable to locate the workpiece also in the other direction in order to preclude even the slightest displacement during or immediately after the striking-out operation.

The workpiece parts to be struck out are preferably applied first only unilaterally, preferably resiliently, on the rams provided for positively vgripping the workpiece parts to be struck out, which are gripped from the other side only thereafter by the action of the rams disposed on this side of the workpiece parts to be struck out.

A device for carrying out said method may be constructed in various ways. Based on the above-mentioned arrangements having a templatelike abutment which serves for supporting the workpiece and is formed with apertures having boundary edges conforming to the boundary lines of the workpiece parts to be struck out, which apertures enables the passage of the struck-out workpiece parts therethrough, such apparatus is preferably characterized in that pairs of rams are provided on both sides of the abutment, which rams are movable towards and from the workpiece and suitably under the influence of a control causing first one of the rams of each pair of rams to engage the workpiece part to be struck out in such a manner that the engaging surfaces coincide or approximately coincide with the interfacial plane between the workpiece and abutment, whereafter the other rams of each pair of rams are applied to the workpiece parts to be struck out, preferably diametrically opposite to the engaging surfaces of the first-mentioned rams; subsequently both rams of each pair of rams in performing the striking-out operation are moved jointly and then relatively to release the workpiece parts which have been subjected to the striking-out and guide movements.

Further details and advantages of the device proposed according to the invention will be described with reference to the drawing, which illustrates an embodiment of the invention in an example consisting of an automatic punching machine, in which coupling members provided between the conveyor chains for conveying the workpieces and the gripper rod carriage in their uncoupled position entirely separate the gripper rod carriage from the conveyor chains, which revolve at uniform speed, and in which means are provided for retarding the gripper rod carriages from the speed of the conveyor chains to zero speed or accelerate them from standstill to the speed of the conveyor chains, which means consist, e.g., of cam-controlled toothed segments in mesh with rack portions of the gripper rod carriages so that in conjunction with the arrangement of a rail section which is movable at right angles to the direction of the rail track and under the influence of a control, the gripper rod carriage moved onto said rail section is movable at right angles to the direction of the conveyor chain.

Specifically, FIG. 1 is a longitudinal sectional view showing the automatic punching machine with punching dies, a striking-out device constructed according to the invention and a laying-out device of the automatic punching machine.

FIG. 2 is a vertical cross-sectional view taken through the automatic machine on line IIII of FIG. 1.

FIG. 3 shows the essential parts of the striking-out device in that condition in which a lower ram has just been applied to a punched-out workpiece par-t.

FIG. 4 is a view similar to that of FIG. 3 and shows the parts in the position in which an upper ram has been applied to the same workpiece part.

FIG. 5 is a view similar to those of FIGS. 3 and 4 and shows the parts at the end of their joint downward movement.

FIG. 6 is a view similar to those of FIGS. 3 to 5 and shows the parts at the end of the downward movement of the lower ram and of the upward movement of the upper ram.

FIG. 7 shows the locating of the cross members to the longitudinal members of a grate which carries the rams.

FIG. 8 is a fragmentary vertical sectional view showing the device which is provided outside the automatic punching machine for preparing the cross-members to be interengaged with the longitudinal members with the rams and ram carriers arranged on the cross-members in the correct positions. FIG. 8 shows this device in a condition in which the strip steel die to be used for punching the sheet workpieces has just been introduced into the device.

FIG. 9 shows the device of FIG. 8 in the same sectional view after the removal of the strip steel die.

FIG. 10 is an elevation showing the device on a slightly reduced scale compared to FIGS. 8 and 9, the upper part of the device being again shown in vertical section.

The figures show the stationary lower tool holder 1 and the movable upper tool holder 2 of the punching station of the automatic punching machine. 3 is the frame of the machine. This frame forms the track rails 4 for the gripper carriages 5, which carry the gripper rods 6. Each gripper carriage is formed with a rack 7, which is arranged to mesh with the toothed segments 8 in the feeding station, 9 in the punching station, It in the striking-out station and 11 in the laying-out station. After the gripper rod carriage 5 has been uncoupled in a manner not shown from the conveyor chain not shown either, it is brought to rest by these toothed segments to enable the operations of feeding, punching, striking out and laying out to be performed, as well as a preceding lowering movement whereby an accurate fit is ensured. The same toothed segments accelerate the gripper rod carriages to the conveying speed after the operation has been performed, whereafter the abovementioned clutch connects the gripper rod carriages again to the chain so that the workpiece is conveyed from station to station. In FIG. 1 one of the gripper rod carriages is in the feeding station whereas a second is in the position in which the workpiece 12 is being punched. A third gripper rod carriage has brought a punched workpiece 12 into the striking-out station, in which it rests just on the template-like abutment 13, as is shown in FIGS. 3 to 6. As is also apparent from FIG. 1, a fourth gripper rod carriage is in the laying-out station with the stack 14 and the laying-out table 15.

Referring first to the showing in FIGS. 3 to 6 the striking-out device according to the invention is constructed as follows:

The above-mentioned template-like abutment 13 has a plurality of apertures 16 (FIG. 6), the boundary edges of which agree with the boundary edges of the workpiece parts 17 to be struck out but exceed the same by the above-mentioned clearance. The pinlike rams 18 are arranged below the apertures 16 in such a manner that each aperture 16 has at least one ram 18 associated therewith whereas a plurality of rams 18 are provided when this is required by the size and shape of the apertures 16. The rams 18 are moved and spring-cushioned in the holders 19. The holders 19 are rotatably received in the sliders 21 by means of the bracket plates 20. The sliders 21 embrace the raillike transverse members 22 at 23 like prisms. By means of the screw bolts 24 they carry also the clamping members 25 so that the rams 18 can be moved to any point of the length of the crossmembers 22 by displacing and clamping the sliders 21 on the cross-members 22. As will be described in more detail with reference to the upper part of FIG. 3 and of FIG. 7, the end of each cross-member 22 is arranged to be connected to longitudinal members 26 extending in the direction in which the workpiece is conveyed.

Further rams 27 coaxial with the rams 18 are provided on the other, upper side of the templatelike abutment 13 and of the workpiece 12. As contrasted with the rams 18 below the template 13 these rams 27 are not springcushioned but rigidly afiixed in the rotatable brackets 28, which are substantially identical in construction to the brackets 20 of the lower rams 18. There is a corresponding arrangement of sliders 29, cross-members 30, prismatic guides 31, screw bolts 32 and clamping members 33. The ends of the cross-members can also be moved to any desired positions on longitudinal members 34 extending in the direction in which the workpieces are conveyed. For this purpose the ends 35 are formed with a teeth '36. The teeth 36 can be inserted into the tooth spaces 37 of the rack 38, which is formed by the longitudinal members 34 on their upper face. The longitudinal members 26 are similarly shaped at 39 and the ends of the cross-members 22 form teeth to be inserted into tooth spaces of the rack 39. The cross-members 30 are held in position relative to the longitudinal members 34 by clamping pieces 40, which are to be clamped by screw bolts 41 against the longitudinal members 34. The cross-members 22 are located in the same way in positive relative to the longitudinal members 26. FIG. 4 shows that sliders 29 serve also for receiving the pressure members 42, which are spring-cushioned at 43. These pressure members 42 can apply the workpiece, e.g., the cardboard sheet 12, against the templatelike abutment 13 and hold it in position in the direction from bottom to top when the parts are in the position shown in FIG. 4. Because the apertures 16 are distributed over the entire clear cross-section of the striking-out area or the template 113 and the workpiece 12 and may have various sizes and shapes, a number of cross-members 22, '30 are required to ensure that at least one pair of rams 18, 27 can be applied to each workpiece part to be struck out unless several pairs of rams 18, 27 are provided for a single part to be struck out. As a result, there is a plurality of crossmembers 26, 3t) and these cross-members form together with the longitudinal members 26, 34 a grate. The rotatability of the rams 18, 27 by means of the brackets 29, 28 enables a compensation of the adjusting steps which are due to the fact that the ends of the cross-members 22, 36? can be displaced only from tooth space to tooth space 37. The same rotatability enables the provision of several ram arrangements directly beside each other without mutual interference.

Because the punching tool 44 carried by the upper tool carrier 2 enables the rams 18 to be disposed in the apertures .16 of the template 13 which correspond to the punching lines so that these rams 18 and with them the opposite rams 27 can be moved into the required positions without need for a cooperation of the workpiece, the construction of the striking-out device according to the invention enables the setting-up of the striking-out device at a very early time, when the automatic punching machine is still in operation on different workpieces. This setting of the rams 18, 27 to the template 1% can be eifected outside the machine because a separate device associated with the automatic punching machine comprises pairs of longitudinal members which correspond to the pairs of longitudinal members 26, 34 and are disposed below and above the template 13. When the tooth spaces 37 and/or the teeth preceding or following them are marked with numbers or otherwise it is suflicient, after the above-mentioned adjustment of the pairs of rams 18 to the apertures 16 and after the coaxial alignment of the rams 27, to mark the crossmembers 22, 3b with the number of the tooth space in which they are then received, whereafter the crossmembers 22, 30 carrying the ram arrangement can be removed from the device and inserted into the similarly marked tooth spaces of the longitudinal members 26, 34 of the automatic punching machine in order to render the striking-out device thereof operative.

A control to be described hereinafter imparts the required movements, shown in FIGS. 3 to 6, to the longitudinal members 26, 34, the cross-members 22, 3b and with them the rams 18, 27. A comparison of FIG. 3 with FIG. 6 shows first that the first control operation consists in a raising of the parts 26, 22, 18, to a position in which the upper boundary face 45 of the rams 18 coincides with the interfacial plane 46-46 between the workpiece l2 and the template 13. At this time the rams 27 are still considerably above the parts 17 to be struck out. This end position of the first control operation, shown in FIG. 3, is followed by a second control operation, which consists in lowering the longitudinal members 34 and with them the cross-members 3t and the rams 27. It is seen that the lower boundary face 47 of the rams 27 has engaged the upper boundary face of the workpiece parts 17 to be struck out. At the same time the pressure members 42 have engaged the workpiece 12 to locate the same relative to the template 113. The continuation of this movement is shown in FIG. 5. Now the longitudinal members '26, the cross-members 22 and with them the rams 18 are lowered too so that in the second part of this control operation shown in FIGS. 4 and 5 the rams of each pair of rams 18, 27 move in unison. In and after the position shown in FIG. 4 the workpiece 117 to be struck out in thus gripped between the rams i8, 27 and constrained to follow the joint movement of both rams so that the workpiece parts to be struck out can no longer be folded around the line which has not been completely cut through. On the contrary, the workpiece part 17 to be struck out is positively subjected to the striking-out movement and is moved on a predetermined path, in the present case on the vertical path 48-48, until it is released. The release movement itself is effected in accordance with FIG. 6 by a continued downward movement of the longitudinal member 26 to a small extent and an upward movement of the longitudinal member 34. Thus, the rams 18, 27 separate. Since the supporting area 45 is disposed outside the centre of gravity of the workpiece parts 17 to be struck out, these parts tend to descend by gravity and can be discharged in known manner.

FIG. 2 shows the control of the parts concerned. It is seen first that the movement of the longitudinal members 34 is derived from the movable upper tool carrier 2. This tool carrier has links 4% rotatably connected thereto, which act on the cranks 50. The crankshafts '51 carry levers 52, which are rotatably connected to the rods 53. The rods 53 act on slide blocks 54, which form steps 55 for supporting the longitudinal members 34. The levers 52 being somewhat longer than the cranks 5d, the necessary transmission ratio is obtained because the longitudinal members 34, the cross-members 3t} and the rams 27 must be raised more than the punching tool 44.

Similarly the longitudinal members 26 carrying the cross-members 22 and the rams 18 are supported by slide blocks 56, which are connected by the links 57, 58 to rollers 59 of cams 60, carried by the drive shafts 61. The drive shafts til are connected in a manner not shown in detail with the main crankshaft, which is provided for driving the upper tool carrier 2.

It is in the nature of the invention that it is not restricted to the illustrative embodiment shown. On principle, the striking-out method and the striking out device described can be applied to any desired punching machine. It is particularly suitable, however, to apply them to automatic punching machines in which the workpiece movement is automatically effected so that the working stroke of the striking-out device can be performed in dependence on the operations of the automatic punching machine.

The movement of the struck-out workpiece parts need not be continued only under the action of gravity, but, e.g., by compressed air, suction or mechanical means.

Finally, an advantage of the proposed process resides in that the cross-member 22, 30 with the ram arrangements need not be knocked down into individual components after use but these cross-members with rams in a certain arrangement may be kept on stock so that in the case of a punching job repeated in intervals it is not necessary to set up the automatic punching machine every time.

FIGS. 8 to 10 show the device which is to be used outside the automatic punching machine to enable the arrangement of the rams IS, 27, the ram carriers 20, 21, 24, 25 and 28, 29', 32, 33 on the cross-members 22, 30 and of the cross-members 22, 30 relative to the longitudinal members 26, 34 with the required spacing so that it is sufiicient to find the tooth spaces 37 in the longitudinal members 26, 34 in order to locate the rams 18, 27 immediately in the correct position.

This means that the automatic punching machine may still be in operation While said device shown in FIGS. 8 to ll) serves already for providing that ram arrangement which is required to enable a mechanical ejection of the worpiece parts which have been incised by the next punching tools to be used for punching in the automatic punching machine when said next punching tools have been installed.

For this purpose the device according to FIGS. 8 to 10 is constructed as follows.

The head 62 of a stable displaceable support 63- grips the channel member 64, which is rigidly connected to a second, opposite channel member 6 5. The channel members 64-, 65 serve to receive the guides 66, 67 for racks 68, 69 provided with head members 70, 71, which are firmly connected to longitudinal members 72, which are identical in construction with the longitudinal members 34 in the automatic punching machine itself and have the same tooth arrangement as the latter comprising the tooth spaces 37 and teeth 38. The teeth are also marked with numbers 73. As is shown in FIG. 3, the same numbers are provided on, e.g., struck into the longitudinal members 34. The teeth 36 of the ends 35 of the cross-members 30 are not apparent from FIG. 8 but visible in FIG. 7 and can be received by the tooth spaces 37 of the longitudinal members 72. In accordance therewith the cross-members 3t} carry the fixing bolts 52, the clamping member 33 and the brackets 28 with the rams 27. Of the several cross-members 34 disposed between two opposite longitudinal members 72, only one is shown by way of illustration. The number of cross-members is such that each of the ram carriers and rams faces one workpiece part to be struck out.

The channels 64, 65 carry in the same manner a second arrangement of longitudinal rails 74 below the longitudinal rail arrangement 72. The distance between the two longitudinal rail arrangements corresponds to the distance between the longitudinal rails 26, 34 in FIGS. 3 to 7 when the parts are in the position of FIG. 8. The channels 64, 65 carry further the fixed strips 75, 76, which serve to guide an abutment 13, which corresponds to the templatelike abutment 13 of FIGS. 3 to 7. Further strips 77, 78 serve to support a frame which consists of the longitudinal rails 79 and the cross-rails S0, 81. The shafts 82 apparent from FIG. 9 are rotatably mounted in the cross-rails 80, 81 and carry at their ends bevel wheels 83, 84, which are in mesh with further bevel wheels 85, 86. The shafts 87, 88 carrying the bevel wheels 85, S6 carry also spur gears 89, 90, which are in mesh with the racks 68, 69. Thus, a rotation of either of shafts 87, 88 will be transmitted by the bevel gear carried by said shaft and the shaft 88 to the other bevel gear so that the spur gears 89, 9t meshing with the racks 68, 69 evenly raise or lower the same.

FIG. 8 shows a plate 91 supported on the frame 79, 80, 8d. The same figure shows the punching tool consisting of the carrier plate 92 with the strip steel die members 93 acting jointly as a blanking tool. The strip steel die members 93 extend through the saw cuts in the template 13 so that it is apparent on the surface of the template 13 where the rams 27 must be arranged to enable the striking out of the workpiece portions which are jointly to be removed by the striking-out fingers 18, 27 after the punching tool 92, 93 has been installed in the automatic punching machine.

When the cross-members 30 have thus been arranged according to FIG. 8 at those points of the longitudinal members 72 where they must be disposed to set the rams 27 in a correct position, the template 13, the punching tool 92, 93 and the plate 91 are moved out of the strips 75, 76 so that the parts assume the position shown in FIG. 9. The cross-rails 22 are now engaged with the aid of the teeth 39 on the longitudinal members 74 corresponding to the longitudinal members 26 in FIGS. 3 to 7 in such a position that the rams 18 held by the crossmembers 22 by means of the ram carriers comprising the parts 19, 20, 21 lie exactly diametrically opposite the rams 27. To enable this to be achieved with the highest accuracy, one of the shafts 87, 88 is previously rotated to lower the racks 68, 69 with their heads 70, 71 and the longitudinal member 72 aflixed thereto by that height which corresponds to the height of parts 13, 92, 93, 91. This causes the end faces of rams 13, 27 to lie exactly opposite each other so that the exact aligning of the rams 18 with the rams 27 does not involve any difiiculty.

The device shown in FIGS. 8 to 10 remains in this position until the automatic punching machine has performed its present work. The rams, ram carriers and cross-rails shown in FIGS. 1 to 7 are then removed from the striking-out station of the machine. Thereafter it is ascertained which tooth gap 38 of a longitudinal member 72 had been engaged in the device of FIGS. 8-10 by a specific cross-member. Each tooth space is provided with a separate number of the series of numbers 73. Thereafter the cross-members 30 with the ram carriers and rams afiixed thereto is removed from the device of FIGS. 8 to 10 and is caused to engage that tooth space of the longitudinal rails 34 of FIG. 9 which is marked with the number as the corresponding tooth space in the longitudinal member 72 of the device according to FIGS. 8 to 10. This is repeated until all cross-members 30 are interengaged with the longitudinal members 34 of FIG. 1. The same is then performed with the cross-members 22, which hold the carriers for the rams 18. Again that number which corresponds to the position of a cross-member 22 on the longitudinal members 74 is ascertained in the device according to FIGS. 8 to 10, the position corresponding to that number is sought on the longitudinal memb rs 26 in FIG. 1, and the respective cross-member 2 is caused to interengage with the longitudinal member 26 at the position of this corresponding number. This is repeated until all cross-members 22 have reached in FIG. l the position which corresponds to the position of FIG. 9. The striking-out device is then ready for operation.

What is claimed is:

l. A stripper mechanism for stripping pro-punched portions from a worksheet comprising, in combination, a support; a plate mounted on said support and being formed with at least one aperture therethrough; means for intermittently feeding prepunched worksheets one by one onto one surface of said plate with said pre-punched portion thereof located in the region of said aperture; 21 first stripper member aligned with said aperture and protruding therethrough from one side of said plate and having an end face substantially flush with said one surface of said plate; a second stripper member aligned with said first stripper member and located on the other side of said plate and having an end face spaced from said one surface of said plate; and moving means mounted on said support and operatively connected to said stripper members for first moving said second stripper member toward said first stripper member until the prc-punched portion located in the region of said aperture is clamped between said end faces of said stripper members, for then moving said stripper members together in direction in which the end faces thereof move through said aperture beyond said plate so that the pre-punched portion will be pulled out from the remainder of the sheet supported on said one surface of said plate, for then moving said second stripper member back to its starting position while retaining said first stripper member substantially in its displaced position so as to release said pulled out pre' punched portion at the other side of said plate, and finally moving said first stripper member back to its starting position in which the end face thereof is flush with said one plate surface.

2. A stripper mechanism for stripping pre-punched portions from a worksheet comprising, in combination, a support; a plate mounted on said support and being formed with at least one aperture therethrough; means for intermittently feeding pre-punched worksheets one by one onto one surface of said plate with said pre-punched portion thereof located in the region of said aperture; a first stripper member aligned with said aperture and protruding therethrough from one side of said plate and having an end face substantially flush with said one surface of said plate; a second stripper member aligned with said first stripper member and located on the other side of said plate and having an end face spaced from said one surface of said plate; resilient means supporting one of said stripper members for resilient movement in direction of the axis of said aperture and moving means mounted on said support and operatively connected to said stripper members for first moving said second stripper member toward said first stripper member until the pre-punched portion located in the region of said aperture is clamped between said end faces of said stripper members, for then moving said stripper members together in direction in which the end faces thereof move through said aperture beyond said plate so that the prepunched portion will be pulled out from the remainder of the sheet supported on said one surface of said plate, for then moving said second stripper member back to its starting position While retaining said first stripper member substantially in its displaced position so as to release said pulled out pre-punched portion at the other side of said plate, and finally moving said first stripper member back to its starting position in which the end face thereof is flush with said one plate surface.

3. A stripper mechanism for stripping pre-punched portions from a worksheet comprising, in combination, a support; a plate mounted on said support and being formed with a plurality of closely spaced apertures therethrough; means for intermittently feeding prepunched worksheets one by one onto one surface of said plate with said pre-punched portions thereof respectively located in the regions of at least some of said apertures; a plurality of first stripper pins having each an end face; first support means for adjustably supporting said plurality of first stripper pins so as to align said plurality of first stripper pins respectively with apertures in the region of which pre-punched portions of said sheet are located with said first stripper pins respectively extending through said apertures from one side of said plate and with said end face of each stripper pin substantially flush with said one surface of said plate; a plurality of second stripper pins having each an end face; second support means for adjustably supporting said plurality of second stripper pins so as to align the same respectively with said first stripper pins and for holding said end faces of said second stripper pins spaced from said one surface of said plate; and moving means mounted on said support and operatively connected to said first and second support means for first moving said second support means toward said one surface of said plate until the pre-punched portions are respectively clamped between end faces of aligned stripper pins, for then moving said first and second support means together in direction in which said end faces of said pins move through said apertures beyond said plate so that the pre-punched portions will be pulled from the remainder of the sheet supported on said one surface of said plate, for then moving said second supporting means in opposite direction back to its starting position While retaining said first supporting means substantially in its displaced position so as to release said pulled out pre-punched portions at the other side of said plate, and finally moving said first support means back to its starting position in which the end faces of said first stripper pins are substantially flush with said one surface of said plate.

4. An arrangement as defined in claim 3 in which each of said support means comprises at least one elongated member mounted on said support extending parallel to said one plate surface; a plurality of second elongated members extending transverse to said first elongated member and being mounted thereon spaced from each other and adjustable in direction of the length of said first elongated member; and means for respectively fastening said stripper pins to said plurality of second elongated members adjustable in direction of the length of said second members.

5. An arrangement as defined in claim 4 in which each of the means for fastening the stripper pins includes a pin holder; clamping means adjustable along the length of the respective second elongated member to be clamped thereon in the adjusted position; and an arm carrying at one end thereof said pin holder and being fastened at the other end thereof to said clamping means turnable about an axis substantially parallel to the axis of the pin held by said pin holder.

6. An arrangement as defined in claim 3 in Which each of said support means comprises a pair of elongated racks fixedly mounted on said support and extending spaced from and substantially parallel to each other and substantially parallel to said plate; a plurality of elongated members extending transversely between said racks and having end portions respectively placed between selected teeth of said racks; clamping means for clamping said end portions of said elongated members to said racks; and means for respectively fastening said stripper pins to said plurality of elongated members adjustable in direction of the length thereof.

7. An arrangement as defined in claim 6 and including scale means on said racks having graduations corresponding to the teeth thereof.

8. An arrangement as defined in claim 3 and including a plurality of pressure members mounted on said second support means respectively movable along axes substantially parallel to and spaced from the axes of said second pin members and having each an end face located substantially in one plane with said end faces of said second pin members; and a plurality of spring means rsepectively operatively connected to said pressure members to permit yielding movement of the same relative to said second pin members during movement of said second pin members through said apertures.

References Cited in the file of this patent UNITED STATES PATENTS 1,413,663 Kent Apr. 25, 1922 2,060,863 Hasse NOV. 12,, 1936 2,256,176 Sheperdson Sept. 16, 1941 2,534,922 Mueller Dec. 19, 1950 2,655,842 Baumgartner Oct. 20, 1953 2,695,060 Griz Nov. 23, 1954 2,899,871 Auer Aug. 18, 1959 

